1. Field of the Invention
This invention relates to a coated substance comprising a 5'-ribonucleotide coated with a film-forming agent which melts when it is heated. More particularly, it relates to an oil or fat coated substance comprising a 5'-ribonucleotide and a coating film which does not break or melt at ordinary room temperature when placed in, for example, food containing water during its manufacturing process prior to heating, and which melts and thereby allows the 5'-ribonucleotide to dissolve in the water when it is heated to a high temperature.
2. Discussion of the Background
There are known coated additives for food which comprise cores coated with substances which melt only when they are heated. The cores are, for example, organic acids which are added to boiled fish paste ("kamaboko" in Japanese), sausages, etc. to lower their pH. Other examples of the core substances are 5'-ribonucleotides. The films with which the cores are coated do not melt at ordinary room temperatures and thereby prevent the destruction of the cores by the enzymes which the food contains. Normally, the enzymes lose their activity when they are heated.
Oils or fats, waxes, higher alcohols and gelatin are typically used for coating 5'-ribonucleotides to prevent them from being released at ordinary room temperatures (Japanese Patent Publication No. 3467/1965). Attempts have been made to achieve improved results and include treating the surfaces of 5'-ribonucleotides to make them lipophilic before coating them with oils or fats (Japanese Patent Publication No. 28677/1980) or coating 5'-guanylic acid with a mixture of an organic acid and an oil or fat (Japanese Laid-Open Patent Specification No. 96680/1981).
None of these methods are, however, very effective for preventing 5'-ribonucleotides from being released or lost during the manufacture of food. The products contain only a low percentage of 5'-ribonucleotides.